Door latch operating mechanism



Dec. 2, 1958 R.YM. MINKr-.j '2,862,750

DooR LATCH OPERATING MECHANISM Filed March 5, 195e United States Patentiiice l 'ja y 2,862,750 Patented Dee. 2, 195s 2,862,750 DOOR LATCHOPERATING MECHANISM lobert M. Minke, Toledo, Ohio Application March 5,1956, Serial No. 569,561

2 Claims. (Cl. 292-172) This invention relates to door latch operatingmeans `and is particularly directed to hand operated means remotelypositioned with respect to the conventional door latch operating meansto unlatch and open a swinging door.

The primary object of the invention is to provide a door with auxiliarylatch operating means conveniently located adjacent the bottom of thedoor so that the door can be opened by a child, the arrangement havingparticular utility when used on doors at the top of stairways, forexample.

Further objects and advantages will become apparent from a study of thefollowing description when taken in connection with the accompanyingdrawings, in which:

Figure 1 is front elevation of a door located at the top of a stairwaywhich incorporates a form of the present invention:

Figure 2 is a side elevation of the door latch operating device shown inFigure 1 as applied to the door in place of the usual latch operatingmeans:

Figure 3 is a view taken in the direction of the arrows 3-3 of Figure 2illustrating details of the motion transmitting mechanism for operatingthe door latch:

Figure 4 is a sectional detail view taken substantially on a line 44 ofFigure 2: and

Figure 5 is a fragmentary elevational view of another for-m of motiontransmitting means of the present invention.

As particularly shown in Figure 1, the door latch operating mechanism ofthe present invention has particular utility when used on doors at thetop of stairways, and in like situations. Frequently in such places thedoor is hinged to swing outwardly over the stairs and when childrenattempt to open the door by reaching for the knob in its usual location,they fall or can be knocked down by the swinging of the door. The dangerthus prevalent in such cases is avoided by providing the door latchoperating Aextension illustrated which includes a secondary door knobpreferably located adjacent the bottom of the door within easy reach ofvery small children. This additional or remotely located door knob isoperatively yconnected to the standard or conventional door knob in sucha manner as to impart the usual rotary movement thereto. This isaccomplished by providing the usual door knob spindle with gear meansactuated by a toothed rack which is motivated by the secondary knobY andto which is attached a similar gear means in mesh with the other end ofthe toothed rack.

As shown in Figures 2 and 3, the device consists primarily of anelongated casing vadapted to replace the usual escutcheon plate adjacentthe knob on one side of the door 11. The case 10 may be of sheet metal,plastic, or other suitable material and serves to enclose and separate apair of spaced bracket members 12 and 14 located respectively adjacentthe opposite ends of the casing. The brackets 12 and 14 are so formed soas to provide pockets for the reception `of gears 16 and 17 squarecentral aperture 18 for the reception of the usual knob supporting shaftor spindle 20, which also serves to actuate the latch bolt 22 towithdraw the same from its keeper plate in the usual manner. Brackets 12and 14 are also formed with rack guide portions within the gear pocketsto provide a backing or bearing surface 24 for the toothed ra-ck 26adapted to be reciprocated upon rotation of gears 16 and 17. The rack 26may have teeth 28 in one edge thereof throughout-its length or may beprovided with teeth adjacent its end portions only, as illustrated. Thegear 17 is likewise provided with a square central aperture 29 withinwhich is more or less permanently attached one end of knob supportingshaft 30 -on the other end of which knob 32 is suitably secured. Thecasing 10 and bracket 14 are provided with aligned openings 31 and 33 toreceive the hubs 21 of gear 17. The walls of these openings providebearings for the gear 17, and additionally permit the shaft 30 to beprojected therethrough. Gear 16 is similarly mounted in casing 10 andbracket 12. The unit may be secured -to the face of the door in thedesired position by means of screws 34 in apertures 36 provided inspacers 38 arranged adjacent the gears 16 and 17 in the brackets 12 and14.

While the spring provided to normally project the latch bolt 22 into itskeeper is ordinarily sufcient to operate the latch in latchingdirection, additional spring means may be provided in the form of stripsprings 40 secured to assist in projecting the latch bolt outwardlyirrespective of what direction the knobs are turned, as they tend tobias the rack 26 toward its intermediate position. Thus by means of thepresent invention means are provided by which the usual door knob can beoperated by means remotely located from the ordinary latch operatingmeans. While the mechanism illustrated can be completely enclosed by thecasing 10 it will be understood that for purpose of economy, twoseparate casings could as well be provided to actuate gear as theintermediate portion of the toothed rack need not necessarily beenclosed.

Referring to Figure 5, it is to Ibe further understood that the toothedrack could be replaced by an endless link chain such as illustrated at46 for imparting motion in either direction to knob 32 to operate theknob 15 and thus withdraw latch 22.

What is claimed is:

1. An auxiliary door latch operating unit adapted to be installed on oneface of a door having a latching bolt and an operating shaft adapted toretract the latching bolt, said unit comprising an elongated casing, anaper ture in said casing, a centrally apertured gear in said casing forreceiving said operating shaft for rotation therewith, means formounting said gear in said casing with the aperture therein opposite theaperture in said casing, a hand operated auxiliary knob projecting fromsaid casing and remotely located with respect to said shaft, a secondgear in said casing connected to said auxiliary knob for rotationtherewith, mounting bracket means carried by said casing for said secondgear, motion transmitting means interconnecting said gears for rotatingsaid shaft from said auxiliary knob to move the latching bolt fromlatching position, and means associated with said motion transmittingmeans for biasing said motion transmitting means toward an intermediateportion to return the latching bolt to latching position.

2. A deviceaccording to claim l in which the motion transmitting meansis a gear rack having spaced sets of teeth in engagement with the gears,and the biasing means includes a pair of spaced springs in engagementwith the opposite ends of the gear rack.

(References on following page) 3 4 Referljencesg Cited, in the le ofthis patent FOREIGN PATENTS UNITED STATES PATENTS 8,638 Great Britain V4-, V Apr. 22, 1905 525,906 Johnson sept. 11. 1894 1551493 Germany OC-27, 1903 669,825 Edwards Mal'. 12, 1901 OTHER REFERENCES 833,024: ClarkOct. 9., 1906 19116481 Rightmyer May-301933 Publication AmericanBuilder, september 1947, 2,04679o. Y Phimps1 my 7j 1936 page 130.v

